• 환경생물
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• 제36권3호
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• pp.424-437
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• 2018

The incidence of freshwater algal bloom has been increasing globally in recent years and poses a major threat to environmental health. Cyanobacteria are the major component of the bloom forming community that must be monitored frequently. Their morphological identities, however, have remained elusive, due to their small size in cells and morphological resemblances among species. We have analyzed molecular diversity and seasonal changes of cyanobacteria in Paldang Reservoir, Korea, using morphological and 16S rRNA pyrosequencing methods. Samples were collected at monthly intervals from the reservoir March-December 2012. In total, 40 phylotypes of cyanobacteria were identified after comparing 49,131 pyrosequence reads. Cyanobacterial genera such as Anabaena, Aphanizomenon, Microcystis and Synechocystis were predominantly present in samples. However, the majority of cyanobacterial sequences (65.9%) identified in this study were of uncultured origins, not detected morphologically. Relative abundance of cyanobacterial sequences was observed as high in August, with no occurrence in March and December. These results suggested that pyrosequencing approach may reveal cyanobacterial diversity undetected morphologically, and may be used as reference for studying and monitoring cyanobacterial communities in aquatic environments.

• ALGAE
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• 제21권4호
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• pp.349-375
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• 2006

The application of modern ecological, ultrastructural and molecular methods, aided by the cultivation of numerous cyanobacterial morphotypes, has substantially changed our knowledge of these organisms. It has led to major advances in cyanobacterial taxonomy and criteria for their phylogenetic classification. Molecular data provide basic criteria for cyanobacterial taxonomy; however, a correct phylogenetic system cannot be constructed without combining genetic data with knowledge from the previous 150 years research of cyanobacterial diversity. Thus, studies of morphological variation in nature, and modern morphological, ultrastructural, ecophysiological and biochemical characters need to be combined in a “polyphasic” approach. Taxonomic concepts for generic and infrageneric ranks are re-evaluated in light of combined phenotypic and molecular criteria. Despite their usefulness in experimental studies, the limitations of using strains from culture collections for systematic and nomenclatural purposes is highlighted. The need for a continual revision of strain identification and proper nomenclatural practice associated with either the bacteriological or botanical codes is emphasized. Recent advances in taxonomy are highlighted in the context of prospects for understanding cyanobacterial diversity from natural habitats, and the evolutionary and adaptational processes that cyanobacteria undergo.

• Molecules and Cells
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• 제43권6호
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• pp.509-516
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• 2020

To perceive fluctuations in light quality, quantity, and timing, higher plants have evolved diverse photoreceptors including UVR8 (a UV-B photoreceptor), cryptochromes, phototropins, and phytochromes (Phys). In contrast to plants, prokaryotic oxygen-evolving photosynthetic organisms, cyanobacteria, rely mostly on bilin-based photoreceptors, namely, cyanobacterial phytochromes (Cphs) and cyanobacteriochromes (CBCRs), which exhibit structural and functional differences compared with plant Phys. CBCRs comprise varying numbers of light sensing domains with diverse color-tuning mechanisms and signal transmission pathways, allowing cyanobacteria to respond to UV-A, visible, and far-red lights. Recent genomic surveys of filamentous cyanobacteria revealed novel CBCRs with broader chromophore-binding specificity and photocycle protochromicity. Furthermore, a novel Cph lineage has been identified that absorbs blue-violet/yellow-orange light. In this minireview, we briefly discuss the diversity in color sensing and signal transmission mechanisms of Cphs and CBCRs, along with their potential utility in the field of optogenetics.

• 미생물학회지
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• 제41권4호
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• pp.287-292
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• 2005

대청호에서 수화 발생이 빈번한 추소리 수역에서 2005년 3월 15일에 채취한 시료를 대상으로 유전자 분식에 의한 cyanobacteria의 다양성을 조사하였다. rpcBA-Intergenic Spacer (IGS)는 cyanobacteria에 특징적 색소인 phycocyanin을 합성하는 유전자와 유전자 사이의 부분으로, 환경시료에서 cyanobacteria의 다양성을 조사하기에 매우 유용한 기능 유전자이다. cpcBA-IGS를 이용하여 restriction fragment length polymorphism (RELP)으로 cyanobacteria의 다양성을 분석한 결과 Phomidium 속은 58 clones, Anabaena 속은 14 clones, Microcyxtis 속은 4 clones, Spirulina 속은 1 clone 그리고 uncultured cyanobacteria 2 clones가 존재하였다. 전반적으로 Phormidium 속이 우점하였으며, 여름철에 수화를 일으키는 Anabaena 속과 Microcystis 속도 많이 분포하였다. 따라서 cyanobacteria는 cpcBA-IGS와 같은 기능 유전자에 의한 종 동정 및 군집분석이 가능함을 보였다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.33-35
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• 2005

• Environmental Engineering Research
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• 제19권4호
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• pp.317-329
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• 2014

The diversity of cyanobacteria in Sri Lanka was studied in different water reservoirs, paddy fields, brackish water and tsunami affected areas using light microcopy, 16S rRNA sequences, followed by phylogenetic analysis. Based on light microscopy, 24 genera were identified from environmental samples belonging to the orders Chroococcales, Oscillatoriales, Pleurocapsales and Nostocales. In cultures, 33 genera were identified from all five cyanobacterial orders, including Stigonematales. Based on 16S rRNA gene sequences and their morphology, two isolates were identified up to species level, 72 to genus level, one isolate up to family and 11 up to order level. Twelve isolates couldn't be assigned to any taxonomic level. The results of 16S rRNA gene sequences along with the phylogenetic analysis indicated that some cyanobacterial isolates could be accommodated to genus or order level. The 16S rRNA sequence analysis data in this study confirmed that order Nostocales and order Pleurocapsales cyanobacteria are monophyletic while orders Chroococcales, Oscillatoriales and Stigonematales cyanobacteria are polyphyletic. Polyphasic approach including the combination of light microscopy, cultures and the analysis of 16S rRNA gene sequences provide a promising approach to ascertain the diversity of cyanobacteria in different habitats.

• 생태와환경
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• 제33권3호통권91호
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• pp.206-212
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• 2000

남조류 분리균주들은 주어진 배양조건에 따라서 특징적인 세포모양이 결핍되거나 형태가 변형되기 쉽기 때문에, 형태학적으로 종을 정확하게 구분하기 어렵다. 형태학적 지표대신에 단일 혹은 조합된 반복염기를 프라이머로 이용한 repetitive oligonucleotides-primed PCR (ROP-PCR)을 수행하여 담수계 오염을 일으키는 독성 남조류 Anabaena와 Oscillatoria 속의 구성원들의 DNA 밴드양상을 구별하였다. 그람음성 세균에 빈번하게 분포한 것으로 알려진 ERIC및 REP 반복염기, 남조류의 게놈으로부터 파생된 STRRIA와 LTRR 반복염기, 그리고 진핵생물의 반복염기를 이용하여 수행한 ROP-PCR은 남조류 분리균주들의 특이적이고 반복적인 DNA 지문 및 뚜렷한 유전형을 동정하게 하였다. 분리균주의 그룹분석은 ROP-PCR에 이용된 프라이머에 따라서 유의성있는 차이를 나타내었다.

• 환경생물
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• 제29권3호
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• pp.225-235
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• 2011

하절기 수화발생이 빈번한 대청호에서 2003~2005년(3년)에 걸쳐 분자생태학적 방법의 하나인 DGGE를 이용하여 시간에 따른 미생물 군집구조의 변화를 연구하였다. 조사기간 동안 출현한 식물플랑크톤을 형태학적으로 분류한 결과 Cyanophyceae가 우점하였고, 이중에서 Microcystis, Planktothrix (Oscillatoria), Phormidium 그리고 Anabaena 속이 크게 우점하였다. 분자적 군집분석 방법으로서 16S rDNA의 DGGE profile 분석과 계통학적 분류에 의하여 우점하는 미생물 군집의 구조와 다양성을 확인하였다. Microcystis는 조사기간 동안 지속적으로 우점하였으나, Planktothrix는 2003년과 2004년 9월에, Anabaena는 2005년 9월, 그리고 Aphanizomenon은 2003년 8월에 우점하였다. DGGE와 계통분류학적 분석방법은 형태학적 분석법에 의해 얻지 못하는 새로운 정보를 제공하며, 남조류와 수생 세균사이의 상관관계를 추정할 수 있고, 그들의 유전적 다양성을 보다 자세하게 확인할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.1-12
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• 2012

The present study examines the effects of 30 mg/kg butachlor on the cyanobacterial diversity of rice fields in Eastern Uttar Pradesh and Western Bihar in India. A total of 40 samples were grouped into three classes [(i) acidic, (ii) neutral, and (iii) alkaline soils], based on physicochemical and principle component analyses. Acidic soils mainly harbored Westillopsis, Trichormus, Anabaenopsis, and unicellular cyanobacteria; whereas Nostoc, Anabaena, Calothrix, Tolypothrix, and Aulosira were found in neutral and alkaline soils. Molecular characterization using 16S rRNA PCR and DGGE revealed the presence of 13 different phylotypes of cyanobacteria in these samples. Butachlor treatment of the soil samples led to the disappearance of 5 and the emergence of 2 additional phylotypes. A total of 40 DGGE bands showed significant reproducible changes upon treatment with butachlor. Phylogenetic analyses divided the phylotypes into five major clusters exhibiting interesting links with soil pH. Aulosira, Anabaena, Trichormus, and Anabaenopsis were sensitive to butachlor treatment, whereas uncultured cyanobacteria, a chroococcalean member, Westillopsis, Nostoc, Calothrix, Tolypothrix, Rivularia, Gloeotrichia, Fischerella, Leptolyngbya, and Cylindrospermum, appeared to be tolerant against butachlor at their native soil pH. Butachlor-induced inhibition of nitrogen fixation was found to be 65% (maximum) and 33% (minimum) in the soil samples of pH 9.23 and 5.20, respectively. In conclusion, low butachlor doses may prove beneficial in paddy fields having a neutral to alkaline soil pH.

• Journal of Microbiology
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• 제44권6호
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• pp.607-616
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• 2006

Molecular characterization of ten marine cyanobacterial isolates belonging to the order Oscillatoriales was carried out using the phycocyanin locus (cpcBA-IGS) and the 16S-23S internally transcribed spacer region. DNA sequences from the phycocyanin operon discriminated ten genotypes, which corresponded to seven morphotypes identified by traditional microscopic analysis. The cpcB coding region revealed 17% nucleotide variation, while cpcA exhibited 29% variation across the studied species. Phylogenetic analyses support the conclusion that the Phormidium and Leptolyngbya genera are not monophyletic. The nucleotide variations were heterogeneously distributed with no or minimal informative nucleotides. Our results suggest that the discriminatory power of the phycocyanin region varies across the cyanobacterial species and strains. The DNA sequence analysis of the 16S-23S internally transcribed spacer region also supports the polyphyletic nature of the studied oscillatorian cyanobacteria. This study demonstrated that morphologically very similar strains might differ genotypically. Thus, molecular approaches comprising different gene regions in combination with morphological criteria may provide better taxonomical resolution of the order Oscillatoriales.